Comparison of effects of dietary saturated, monounsaturated, and polyunsaturated fatty acids on plasma lipids and lipoproteins in man

Musings about the role dietary fats after 40 years of fatty acid research

Since the 1950's nutrition recommendations have focussed on the replacement of saturated fats in the diet with polyunsaturated fats, a strategy that continues to this day. Despite supporting evidence from clinical trials for the advantages of Mediterranean diets, there has been less attention paid to the role of monounsaturated fats. It has been known for many years that diets high in linoleic acid (LA) compete for the incorporation of omega 3 fatty acids into tissues. What is also clear is that diets rich in LA are not free from concerns and the discovery of oxlams, oxygenated derivatives of LA, having potent inflammatory effects may help us question the dogma of LA rich diets. Given that dietary oleic acid a prime constituent of Mediterranean diets can be metabolised to Mead acid (ETrA) has in the past been a cause for concern, but new data showing the anti-inflammatory effects of ETrA suggest that there is a need for further research about the benefits of monounsaturated oils on human health. Finally, there is a need to re-examine how dietary fats are monitored in clinical studies. The current method of focussing on esterified fatty acids may be too insensitive to detect clinically important changes.

Nutritional assessment of Esmeraldan adult population (Ecuador)

ABSTRACT Objective To analyse the nutritional status of the adult population in Esmeraldas by means of anthropometric measurements, the input of macro and micronutrients in the diet, and the adequacy estimation of nutrient intake by hispanic Dietary Reference Instakes along with the sex and the age influence. Methods Nutrient intake data were obtained by personal interview with the application of two 24 hour recalls (weekend and weekday). The anthropometric indicators analysed were body mass index, waist circumference and blood pressure. Nutriplato version 2.0 software was used for the two 24-hours food recall surveys data processing, and for the respective calculations of macronutrients, micronutrients and Dietary Reference Intakes. Means and standard deviations were calculated for anthropometry, nutrient intakes and Dietary Reference Instakes. The General Linear Model was applied to identify differences in relation to nutrient intakes considering sex, profession, body mass index, group, origin and day of the week as factors. Results Statistical analysis showed significant differences mainly in carbohydrates, fiber, calcium, phosphorus, iron, sodium, iodine, and vitamin E. Dietary intakes were compared with the Federación Española de Sociedades de Nutrición, Alimentación y Dietética Dietary Reference Intakes requirements and calcium, potassium, iodine, riboflavin, pantothenic acid, biotin, vitamin D, vitamin E, fiber, monounsaturated fatty acids and polyunsaturated fatty acids are below the Dietary Reference Instakes in all ages and gender subgroups. The anthropometric results obtained indicated that 67.0% of the population were overweight and obese, the 87.7% of the adults suffered from prehypertension and the waist circumference indicated that 73.0% of the subjects were established in the range of high risk of cardiovascular disease. Conclusion Priority nutrition actions and interventions are needed to be developed in Esmeraldas adult population.

Effects of Different Pretreatments to Fresh Fruit on Chemical and Thermal Characteristics of Crude Palm Oil

This study selected 5 methods, including boiling, hot air drying, high-pressurized steam, freezing, and microwave radiation to pretreat fresh oil palm fruit before solvent extraction of the oil. Using fresh fruit as a control, the pretreatment methods were compared for the effects on the activity of the 2 main enzymes in the fruit and some physicochemical properties of the crude palm oil. The results indicated, although all the 5 pretreatments could inactivate lipase and peroxidase in the treated flesh significantly (P < 0.05), the high-pressurized steam was the most effective. There were also differences in the unsaturated fatty acid contents of the 6 oils. The crude oil from frozen fruit contained significantly more vitamin E (37829.33 ppm) than previously reported. Microwave radiation was shown to significantly decrease the free fatty acid content and the peroxide value, while increasing the oxidative stability index. Thermal behaviors of the oils were significantly different to each other with the exception a few parameters (P < 0.05).

Rare Hybrid Dimers with Anti-Acetylcholinesterase Activities from a Safflower (Carthamus tinctorius L.) Seed Oil Cake

Safflower (Carthamus tinctorius) is commercially cultivated for vegetable oil extracted from the seeds. However, during the production process of seed oil, a large amount of the oil cake is thrown away or fermented as fertilizer to improve the homing rate of pigeons. Therefore, to solve the ecological problem and develop its new function, we investigated the chemical constituents of a safflower seed oil cake, and six new hybrid dimers, (±)-carthatins A-F (1-6, respectively), with a phenylpropanoid and a feruloylserotonin fused via a dihydrofuran ring, together with four known compounds, including sinapyl alcohol (7), coniferyl alcohol (8), serotobenine (9), and feruloylserotonin (10), were isolated. The extensive nuclear magnetic resonance spectra, combined with electronic circular dichroism analysis and chiral high-performance liquid chromatography, allowed the complete structural assignments of (±)-carthatins A-F. Moreover, we evaluated their anti-acetylcholinesterase activities. Racemic carthatins A and B (1 and 2, respectively) showed anti-acetylcholinesterase effects with IC₅₀ values of 17.96 and 66.83 μM, respectively. To some extent, our findings provide a new scaffold of acetylcholinesterase inhibitors, which could be beneficial for developing therapeutic molecules for the treatment of Alzheimer's disease and supporting folk application of a safflower seed oil cake.

Melatonin prevents memory impairment induced by high-fat diet: Role of oxidative stress

Consumption of high-fat diet (HFD) induces oxidative stress in the hippocampus that leads to memory impairment. Melatonin has antioxidant and neuroprotective effects. In this study, we hypothesized that chronic administration of melatonin can prevent memory impairment induced by consumption of HFD. Melatonin was administered to rats via oral gavage (100mg/kg/day) for 4 weeks. HFD was also instituted for the same duration. Behavioral studies were conducted to test spatial memory using the radial arm water maze. Additionally, oxidative stress biomarkers were assessed in the hippocampus. Results showed that HFD impaired both short- and long- term memory (P<0.05), while melatonin treatment prevented such effects. Furthermore, melatonin prevented HFD-induced reduction in levels of GSH, and ratio of GSH/GSSG, and increase in GSSG in the hippocampus. Melatonin also prevented reduction in the catalase activity in hippocampus of animals on HFD. In conclusion, HFD induced memory impairment and melatonin prevented this impairment probably by preventing alteration of oxidative stress in the hippocampus.

Role of Total, Red, Processed, and White Meat Consumption in Stroke Incidence and Mortality: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Background

Previous meta‐analyses on meat intake and risk of stroke did not report the effect of white meat (poultry meat, excluding fish) and did not examine stroke incidence and mortality separately. We aimed to investigate the relationship of total (red and processed meat), red (unprocessed or fresh red meat), and processed (processed red meat) consumption along with white meat on risk of stroke incidence and mortality.

Methods and Results

Articles were identified from databases and reference lists of relevant studies up to October 28, 2016. We selected prospective cohort studies on meat consumption specified by types of meat and stroke incidence and mortality reporting relative risks and 95% confidence intervals. The pooled relative risk was estimated using the random‐effects model. Based on the inclusion criteria, 10 articles containing 15 studies (5 articles with 7 studies including 9522 cases of stroke incidence and 254 742 participants and 5 articles with 8 studies containing 12 999 cases of stroke mortality and 487 150 participants) were selected for quantitative synthesis. The pooled relative risks (95% confidence intervals) for total, red, processed and white meat consumption and total stroke incidence were 1.18 (1.09–1.28), 1.11 (1.03–1.20), 1.17 (1.08–1.25), and 0.87 (0.78–0.97), respectively. Total meat consumption (0.97 [0.85–1.11]) and red meat consumption 0.87 (0.64–1.18) were not significantly associated with stroke‐related death.

Conclusions

The relationship between meat intake and risk of stroke may differ by type of meat. Recommendations for replacing proportions of red and processed meats to white meat for the prevention of stroke may be considered in clinical practice.

Membrane lipid alterations in the metabolic syndrome and the role of dietary oils

The metabolic syndrome is a cluster of pathological conditions, including hypertension, hyperglycemia, hypertriglyceridemia, obesity and low HDL levels that is of great concern worldwide, as individuals with metabolic syndrome have an increased risk of type-2 diabetes and cardiovascular disease. Insulin resistance, the key feature of the metabolic syndrome, might be at the same time cause and consequence of impaired lipid composition in plasma membranes of insulin-sensitive tissues like liver, muscle and adipose tissue. Diet intervention has been proposed as a powerful tool to prevent the development of the metabolic syndrome, since healthy diets have been shown to have a protective role against the components of the metabolic syndrome. Particularly, dietary fatty acids are capable of modulating the deleterious effects of these conditions, among other mechanisms, by modifications of the lipid composition of the membranes in insulin-sensitive tissues. However, there is still scarce data based of high-level evidence on the effects of dietary oils on the effects of the metabolic syndrome and its components. This review summarizes the current knowledge on the effects of dietary oils on improving alterations of the components of the metabolic syndrome. It also examines their influence in the modulation of plasma membrane lipid composition and in the functionality of membrane proteins involved in insulin activity, like the insulin receptor, GLUT-4, CD36/FAT and ABCA-1, and their effect in the metabolism of glucose, fatty acids and cholesterol, and, in turn, the key features of the metabolic syndrome. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.

Scavenger Receptor Class B, Type I, a CD36 Related Protein in Macrobrachium nipponense: Characterization, RNA Interference, and Expression Analysis with Different Dietary Lipid Sources

The scavenger receptor class B, type I (SR-BI), is a member of the CD36 superfamily comprising transmembrane proteins involved in mammalian and fish lipid homeostasis regulation. We hypothesize that this receptor plays an important role in Macrobrachium nipponense lipid metabolism. However, little attention has been paid to SR-BI in commercial crustaceans. In the present study, we report a cDNA encoding M. nipponense scavenger receptor class B, type I (designated as MnSR-BI), obtained from a hepatopancreas cDNA library. The complete MnSR-BI coding sequence was 1545 bp, encoding 514 amino acid peptides. The MnSR-BI primary structure consisted of a CD36 domain that contained two transmembrane regions at the N- and C-terminals of the protein. SR-BI mRNA expression was specifically detected in muscle, gill, ovum, intestine, hepatopancreas, stomach, and ovary tissues. Furthermore, its expression in the hepatopancreas was regulated by dietary lipid sources, with prawns fed soybean and linseed oils exhibiting higher expression levels. RNAi-based SR-BI silencing resulted in the suppression of its expression in the hepatopancreas and variation in the expression of lipid metabolism-related genes. This is the first report of SR-BI in freshwater prawns and provides the basis for further studies on SR-BI in crustaceans.

Stearoyl-CoA Desaturase-1 Protects Cells against Lipotoxicity-Mediated Apoptosis in Proximal Tubular Cells

Saturated fatty acid (SFA)-related lipotoxicity is a pathogenesis of diabetes-related renal proximal tubular epithelial cell (PTEC) damage, closely associated with a progressive decline in renal function. This study was designed to identify a free fatty acid (FFA) metabolism-related enzyme that can protect PTECs from SFA-related lipotoxicity. Among several enzymes involved in FFA metabolism, we identified stearoyl-CoA desaturase-1 (SCD1), whose expression level significantly decreased in the kidneys of high-fat diet (HFD)-induced diabetic mice, compared with non-diabetic mice. SCD1 is an enzyme that desaturates SFAs, converting them to monounsaturated fatty acids (MUFAs), leading to the formation of neutral lipid droplets. In culture, retrovirus-mediated overexpression of SCD1 or MUFA treatment significantly ameliorated SFA-induced apoptosis in PTECs by enhancing intracellular lipid droplet formation. In contrast, siRNA against SCD1 exacerbated the apoptosis. Both overexpression of SCD1 and MUFA treatment reduced SFA-induced apoptosis via reducing endoplasmic reticulum stress in cultured PTECs. Thus, HFD-induced decrease in renal SCD1 expression may play a pathogenic role in lipotoxicity-induced renal injury, and enhancing SCD1-mediated desaturation of SFA and subsequent formation of neutral lipid droplets may become a promising therapeutic target to reduce SFA-induced lipotoxicity. The present study provides a novel insight into lipotoxicity in the pathogenesis of diabetic nephropathy.

Effects of super-hard rice bread blended with black rice bran on amyloid β peptide production and abrupt increase in postprandial blood glucose levels in mice

Alzheimer's disease and type 2 diabetes are very serious diseases with the latter having been suggested to cause the former. We prepared super-hard rice bread blended with black rice bran (SRBBB), which contained a high amount of resistant starch that showed strong inhibitory activities against β-secretase and acetylcholinesterase even after heating. Black rice bran showed greater β-secretase inhibitory activity (3.6-fold) than Koshihikari rice. The bran contained more oleic acid and anthocyanin, meaning that it is potentially a biofunctional food with a high antioxidant capacity. Furthermore, aged mice, which were fed a SRBBB diet for four weeks, showed lower amyloid β 40 peptide in the blood than mice fed a commercial diet (p < 0.01). Additionally, their initial blood glucose levels (BGLs) after 12 weeks of being fed SRBBB were significantly lower than those in the control group. Taken together, our results indicate SRBBB shows promise for inhibiting not only amyloid β production, but also abrupt increases in postprandial BGLs.

Genotype-related variations in subcutaneous fat composition in sheep

The aim of this research was to study the effect of genotype on the fatty acid composition in adult ewes and 5-to 6-month-old lambs of two mutton breeds (Suffolk and Pannon Sheep) and Booroola Merino. Samples of subcutaneous fat were obtained by surgical biopsy around the tailhead. Fatty acid composition of the adipose fat was determined by gas chromatography. Significant differences (P < 0·05) were found in the fatty acid composition of the adipose tissue among the three breeds. Suffolk showed a lower (P < 0·05) proportion of C12: 0 and C14: 0 fatty acids than the other two breeds. Considering the total quantity of saturated (TSFA) and the total quantity of unsaturated (TUFA) fatty acids, Booroola Merino showed a significantly (P < 0·05) higher proportion of TSFA and lower proportion of TUFA in their adipose tissue than the mutton genotypes (Suffolk and Pannon Sheep). Higher proportions of C18: 0, C18: 3 and C20: 1 (P < 0·05) but lower proportions of C12: 0, C14: 0, C16: 0, C16: 1 and C18: 2 (P < 0·05) were found in the subcutaneous fat of adult ewes than in that of their female progeny. Sex differences were also observed in the study. The proportions of saturated fatty acids were higher (P < 0·05) in female lambs than in males of the same age. These results indicate that a genetic approach may be useful to improve fatty acid composition of carcass lipids in sheep. However, age and sex differences also have to be taken into consideration.

Comparing effects of soybean oil- and palm olein-based mayonnaise consumption on the plasma lipid and lipoprotein profiles in human subjects: a double-blind randomized controlled trial with cross-over design

BACKGROUND

Mayonnaise is used widely in contemporary human diet with widespread use as a salad dressing or spread on breads. Vegetable oils used in its formulation may be a rich source of ω-6 PUFAs and the higher-PUFA content of mayonnaise may be beneficial in mediating a hypocholesterolemic effect. This study, therefore, evaluated the functionality of mayonnaise on cardiometabolic risk within a regular human consumption scenario.

METHODS

Subjects underwent a randomized double-blind crossover trial, consuming diets supplemented with 20 g/day of either soybean oil-based mayonnaise (SB-mayo) or palm olein-based mayonnaise (PO-mayo) for 4 weeks each with a 2-week wash-out period. The magnitude of changes for metabolic outcomes between dietary treatments was compared with PO-mayo serving as the control. The data was analyzed by ANCOVA using the GLM model. Analysis was adjusted for weight changes.

RESULTS

Treatments resulted in significant reductions in TC (diff = -0.25 mmol/L; P = 0.001), LDL-C (diff = -0.17 mmol/L; P = 0.016) and HDL-C (diff = -0.12 mmol/L; P < 0.001) in SB-mayo compared to PO-mayo without affecting LDL-C:HDL-C ratio (P > 0.05). Lipoprotein particle change was significant with large LDL particles increasing after PO-mayo (diff = +63.2 nmol/L; P = 0.007) compared to SB-mayo but small LDL particles remained unaffected. Plasma glucose, apolipoproteins and oxidative stress markers remained unchanged.

CONCLUSIONS

Daily use with 20 g of linoleic acid-rich SB-mayo elicited reductions in TC and LDL-C concentrations without significantly changing LDL-C:HDL-C ratio or small LDL particle distributions compared to the PO-mayo diet.

TRIAL REGISTRATION

This clinical trial was retrospectively registered with the National Medical Research Register, National Institute of Health, Ministry of Health Malaysia, (NMRR-15-40-24035; registered on 29/01/2015; https://www.nmrr.gov.my/fwbPage.jsp?fwbPageId=ResearchISRForm&fwbAction=Update&fwbStep=10&pk.researchID=24035&fwbVMenu=3&fwbResearchAction=Update ). Ethical approval was obtained from the National University of Malaysia's Medical Ethics Committee (UKM 1.5.3.5/244/SPP/NN-054-2011, approved on 25/05/2011).

Effects of Serum Triglycerides on Prostate Cancer and Breast Cancer Risk: A Meta-Analysis of Prospective Studies

Epidemiological studies show conflicting results regarding the link between serum triglyceride and the risk of prostate cancer and breast cancer. Therefore, we performed a meta-analysis of prospective studies to clarify this association. We searched PubMed, EMBASE, the Chinese Biomedical Database (CBM), and the China National Knowledge Infrastructure (CNKI) database to identify relevant prospective studies of the relationship between serum triglyceride and prostate cancer and breast cancer risk. Study-specific estimates adjusting for potential confounders were combined to evaluate a summary relative risks (RRs) and 95% confidence intervals (95% CIs) using a fixed- or random-effects model. A total of 11 prospective studies (619,410 subjects and 15,691 incident prostate cancer patients) and 8 prospective studies (590,878 subjects and 12,177 incident breast cancer patients) were respectively included in our meta-analysis to assess the associations of serum triglyceride with prostate cancer and breast cancer risk. The pooled adjusted RR estimates for prostate cancer and breast cancer for the highest versus the lowest exposure levels of serum triglycerides were 0.95 (95% CI: 0.87-1.04) and 0.94 (95% CI: 0.87-1.00), respectively. Additionally, a dose-response analysis revealed that serum levels of triglycerides were not associated with the risk of prostate cancer and breast cancer. We found that serum triglyceride was not related to the risk of prostate cancer and breast cancer.

Emu oil decreases atherogenic plaque formation in cafeteria diet-induced obese rats

BACKGROUND

Atherosclerosis-induced coronary heart disease - caused by elevated levels of low-density lipoproteins (LDL) and inflammation - is one of the most prevalent diseases. Monounsaturated fatty acids are reported to prevent atherosclerosis; emu oil is a rich source of monounsaturated fatty acid, and we hypothesize that emu oil supplementation could lower inflammation and prevent atherosclerosis in diet-induced obese (DIO) animals. Male Wistar rats were randomly divided into five groups (n = 6), and fed with normal diet (chow pellet; ND), or with cafeteria diet (CD), or with CD along with emu oil supplementation at three different doses: ED1 (2 mL), ED2 (4 mL) and ED3 (8 mL) kg(-1) body weight (BW), respectively.

RESULTS

After 12 weeks, the animals were sacrificed and serum was analysed for measuring lipid profile, C-reactive proteins, testosterone and luteinizing hormone. Histopathological studies were performed to observe atherogenic changes in thoracic aorta. Restoration of altered lipid and hormonal profiles, and inhibition of atherogenic changes in thoracic aorta, were observed with supplementation of emu oil, confirming its anti-atherosclerotic activity.

CONCLUSION

The high content of oleic acid in emu oil could have orchestrated - either solely or in combination with linoleic and linolenic acids - causing the upregulation of testosterone biosynthesis and inhibition of atheromatous plaque formation in diet-induced obese animals. © 2015 Society of Chemical Industry.

Edible seaweed as future functional food: Identification of α-glucosidase inhibitors by combined use of high-resolution α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR

Crude chloroform, ethanol and acetone extracts of nineteen seaweed species were screened for their antioxidant and α-glucosidase inhibitory activity. Samples showing more than 60% α-glucosidase inhibitory activity, at a concentration of 1 mg/ml, were furthermore investigated using high-resolution α-glucosidase inhibition profiling combined with high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HR-bioassay/HPLC-HRMS-SPE-NMR). The results showed Ascophyllum nodosum and Fucus vesicolosus to be rich in antioxidants, equaling a Trolox equivalent antioxidant capacity of 135 and 108 mM Troloxmg(-1) extract, respectively. HR-bioassay/HPLC-HRMS-SPE-NMR showed the α-glucosidase inhibitory activity of A. nodosum, F. vesoculosus, Laminaria digitata, Laminaria japonica and Undaria pinnatifida to be caused by phlorotannins as well as fatty acids - with oleic acid, linoleic acid and eicosapentaenoic acid being the most potent with IC50 values of 0.069, 0.075 and 0.10 mM, respectively, and showing a mixed-type inhibition mode.

Pineapple by-product and canola oil as partial fat replacers in low-fat beef burger: Effects on oxidative stability, cholesterol content and fatty acid profile

The effect of freeze-dried pineapple by-product and canola oil as fat replacers on the oxidative stability, cholesterol content and fatty acid profile of low-fat beef burgers was evaluated. Five treatments were performed: conventional (CN, 20% fat) and four low-fat formulations (10% fat): control (CT), pineapple by-product (PA), canola oil (CO), and pineapple by-product and canola oil (PC). Low-fat cooked burgers showed a mean cholesterol content reduction of 9.15% compared to the CN. Canola oil addition improved the fatty acid profile of the burgers, with increase in the polyunsaturated/saturated fatty acids ratio and decrease in the n-6/n-3 ratio, in the atherogenic and thrombogenic indexes. The oxidative stability of the burgers was affected by the vegetable oil addition. However, at the end of the storage time (120 days), malonaldehyde values of CO and PC were lower than the threshold for the consumer's acceptance. Canola oil, in combination with pineapple by-product, can be considered promising fat replacers in the development of healthier burgers.

Myristic acid is associated to low plasma HDL cholesterol levels in a Mediterranean population and increases HDL catabolism by enhancing HDL particles trapping to cell surface proteoglycans in a liver hepatoma cell model

BACKGROUND

HDL-C plasma levels are modulated by dietary fatty acid (FA), but studies investigating dietary supplementation in FA gave contrasting results. Saturated FA increased HDL-C levels only in some studies. Mono-unsaturated FA exerted a slight effect while poly-unsaturated FA mostly increased plasma HDL-C.

AIMS

This study presents two aims: i) to investigate the relationship between HDL-C levels and plasma FA composition in a Sicilian population following a "Mediterranean diet", ii) to investigate if FA that resulted correlated with plasma HDL-C levels in the population study and/or very abundant in the plasma were able to affect HDL catabolism in an "in vitro" model of cultured hepatoma cells (HepG2).

RESULTS

plasma HDL-C levels in the population correlated negatively with myristic acid (C14:0, β = -0.24, p < 0.01), oleic acid (C18:1n9, β = -0.22, p < 0.01) and cis-11-Eicosenoic (C20:1n9, β = -0.19, p = 0.01) and positively with palmitoleic acid (C16:1, β = +0.19, p = 0.03). HepG2 cells were conditioned with FA before evaluating HDL binding kinetics, and only C14:0 increased HDL binding by a non-saturable pathway. After removal of heparan sulphate proteoglycans (HSPG) by heparinases HDL binding dropped by 29% only in C14:0 conditioned cells (p < 0.05). C14:0 showed also the highest internalization of HDL-derived cholesteryl esters (CE, +32% p = 0.01 vs. non-conditioned cells).

CONCLUSIONS

C14:0 was correlated with decreased plasma HDL-C levels in a Mediterranean population. C14:0 might reduce HDL-C levels by increasing HDL trapping to cell surface HSPG and CE stripping from bound HDL. Other mechanisms are to be investigated to explain the effects of other FA on HDL metabolism.

Selenium Content in the Liver of Wistar Rats Fed Diets of Different Fatty Acid Quality

The purpose of this work was to measure the amounts of selected mineral elements (sodium, calcium, iron, selenium, magnesium, zinc, copper, and manganese) in the liver of Wistar rats and evaluate possible correlations between the levels of these minerals and the lipid metabolism in the studied animals. Three experimental groups each containing six Wistar rats were designed. Each group was fed a different diet. The control group was fed a diet prepared with fresh soybean oil and named control group--CG. The second group (named experimental group B--EGB) and third group (named experimental group C--EGC) were fed a diet containing soybean oil that had been used to fry different foods for four or ten cycles, respectively. The mineral elements in Wistar rat livers were measured by inductively coupled plasma optical emission spectrometry (ICP OES). Only the elements calcium and selenium differed significantly between the control and experimental groups. There was a significant reduction of 33% for Ca and 41% for Se in the EGB in comparison to the control group. The reduction in mineral concentration, especially Se, is the result of interactions with fatty acid metabolism. The animals in the EGC exhibited more intracytoplasmic accumulation of fat and more intense vasodilatation, in relation to the other groups. Collectively, evidence hereby collected suggests that impaired dietary lipid quality in otherwise balanced diets can reduce hepatic Se levels and potentially harm liver function.

A systematic review of high-oleic vegetable oil substitutions for other fats and oils on cardiovascular disease risk factors: implications for novel high-oleic soybean oils

High-oleic acid soybean oil (H-OSBO) is a trait-enhanced vegetable oil containing >70% oleic acid. Developed as an alternative for trans-FA (TFA)-containing vegetable oils, H-OSBO is predicted to replace large amounts of soybean oil in the US diet. However, there is little evidence concerning the effects of H-OSBO on coronary heart disease (CHD)(6) risk factors and CHD risk. We examined and quantified the effects of substituting high-oleic acid (HO) oils for fats and oils rich in saturated FAs (SFAs), TFAs, or n-6 (ω-6) polyunsaturated FAs (PUFAs) on blood lipids in controlled clinical trials. Searches of online databases through June 2014 were used to select studies that defined subject characteristics; described control and intervention diets; substituted HO oils compositionally similar to H-OSBO (i.e., ≥70% oleic acid) for equivalent amounts of oils high in SFAs, TFAs, or n-6 PUFAs for ≥3 wk; and reported changes in blood lipids. Studies that replaced saturated fats or oils with HO oils showed significant reductions in total cholesterol (TC), LDL cholesterol, and apolipoprotein B (apoB) (P < 0.05; mean percentage of change: -8.0%, -10.9%, -7.9%, respectively), whereas most showed no changes in HDL cholesterol, triglycerides (TGs), the ratio of TC to HDL cholesterol (TC:HDL cholesterol), and apolipoprotein A-1 (apoA-1). Replacing TFA-containing oil sources with HO oils showed significant reductions in TC, LDL cholesterol, apoB, TGs, TC:HDL cholesterol and increased HDL cholesterol and apoA-1 (mean percentage of change: -5.7%, -9.2%, -7.3%, -11.7%, -12.1%, 5.6%, 3.7%, respectively; P < 0.05). In most studies that replaced oils high in n-6 PUFAs with equivalent amounts of HO oils, TC, LDL cholesterol, TGs, HDL cholesterol, apoA-1, and TC:HDL cholesterol did not change. These findings suggest that replacing fats and oils high in SFAs or TFAs with either H-OSBO or oils high in n-6 PUFAs would have favorable and comparable effects on plasma lipid risk factors and overall CHD risk.

Aberrant de novo cholesterogenesis: Clinical significance and implications

Human cells can acquire cholesterol from the circulation but also have the ability to synthesize it via de novo cholesterogenesis (DC). Cholesterol absorption and de novo cholesterogenesis are the key processes that modulate cholesterol homeostasis in the human body. The endogenous biosynthesis of cholesterol substantially contributes to the whole-body cholesterol pool. Additionally, dysregulation of this pathway is associated with diverse medical conditions. The present review focuses on our current understanding of the cholesterogenic pathway and the various different factors regulating this pathway. It also highlights dysregulation of this pathway in various physiological and pathological conditions including cardiovascular diseases, type II diabetes, obesity and viral infections.

Diets with high-fat cheese, high-fat meat, or carbohydrate on cardiovascular risk markers in overweight postmenopausal women: a randomized crossover trial

BACKGROUND

Heart associations recommend limited intake of saturated fat. However, effects of saturated fat on low-density lipoprotein (LDL)-cholesterol concentrations and cardiovascular disease risk might depend on nutrients and specific saturated fatty acids (SFAs) in food.

OBJECTIVE

We explored the effects of cheese and meat as sources of SFAs or isocaloric replacement with carbohydrates on blood lipids, lipoproteins, and fecal excretion of fat and bile acids.

DESIGN

The study was a randomized, crossover, open-label intervention in 14 overweight postmenopausal women. Three full-diet periods of 2-wk duration were provided separated by 2-wk washout periods. The isocaloric diets were as follows: 1) a high-cheese (96-120-g) intervention [i.e., intervention containing cheese (CHEESE)], 2) a macronutrient-matched nondairy, high-meat control [i.e., nondairy control with a high content of high-fat processed and unprocessed meat in amounts matching the saturated fat content from cheese in the intervention containing cheese (MEAT)], and 3) a nondairy, low-fat, high-carbohydrate control (i.e., nondairy low-fat control in which the energy from cheese fat and protein was isocalorically replaced by carbohydrates and lean meat (CARB).

RESULTS

The CHEESE diet caused a 5% higher high-density lipoprotein (HDL)-cholesterol concentration (P = 0.012), an 8% higher apo A-I concentration (P < 0.001), and a 5% lower apoB:apo A-I ratio (P = 0.008) than did the CARB diet. Also, the MEAT diet caused an 8% higher HDL-cholesterol concentration (P < 0.001) and a 4% higher apo A-I concentration (P = 0.033) than did the CARB diet. Total cholesterol, LDL cholesterol, apoB, and triacylglycerol were similar with the 3 diets. Fecal fat excretion was 1.8 and 0.9 g higher with the CHEESE diet than with CARB and MEAT diets (P < 0.001 and P = 0.004, respectively) and 0.9 g higher with the MEAT diet than with the CARB diet (P = 0.005). CHEESE and MEAT diets caused higher fecal bile acid excretion than did the CARB diet (P < 0.05 and P = 0.006, respectively). The dominant type of bile acids excreted differed between CHEESE and MEAT diets.

CONCLUSIONS

Diets with cheese and meat as primary sources of SFAs cause higher HDL cholesterol and apo A-I and, therefore, appear to be less atherogenic than is a low-fat, high-carbohydrate diet. Also, our findings confirm that cheese increases fecal fat excretion. This trial was registered at clinicaltrials.gov as NCT01739153.

Effects of total fat intake on body weight

BACKGROUND

In order to prevent overweight and obesity in the general population we need to understand the relationship between the proportion of energy from fat and resulting weight and body fatness in the general population.

OBJECTIVES

To assess the effects of proportion of energy intake from fat on measures of weight and body fatness (including obesity, waist circumference and body mass index) in people not aiming to lose weight, using all appropriate randomised controlled trials (RCTs) and cohort studies in adults, children and young people

SEARCH METHODS

We searched CENTRAL to March 2014 and MEDLINE, EMBASE and CINAHL to November 2014. We did not limit the search by language. We also checked the references of relevant reviews.

SELECTION CRITERIA

Trials fulfilled the following criteria: 1) randomised intervention trial, 2) included children (aged ≥ 24 months), young people or adults, 3) randomised to a lower fat versus usual or moderate fat diet, without the intention to reduce weight in any participants, 4) not multifactorial and 5) assessed a measure of weight or body fatness after at least six months. We also included cohort studies in children, young people and adults that assessed the proportion of energy from fat at baseline and assessed the relationship with body weight or fatness after at least one year. We duplicated inclusion decisions and resolved disagreement by discussion or referral to a third party.

DATA COLLECTION AND ANALYSIS

We extracted data on the population, intervention, control and outcome measures in duplicate. We extracted measures of weight and body fatness independently in duplicate at all available time points. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity and funnel plot analyses.

MAIN RESULTS

We included 32 RCTs (approximately 54,000 participants) and 30 sets of analyses of 25 cohorts. There is consistent evidence from RCTs in adults of a small weight-reducing effect of eating a smaller proportion of energy from fat; this was seen in almost all included studies and was highly resistant to sensitivity analyses. The effect of eating less fat (compared with usual diet) is a mean weight reduction of 1.5 kg (95% confidence interval (CI) -2.0 to -1.1 kg), but greater weight loss results from greater fat reductions. The size of the effect on weight does not alter over time and is mirrored by reductions in body mass index (BMI) (-0.5 kg/m(2), 95% CI -0.7 to -0.3) and waist circumference (-0.3 cm, 95% CI -0.6 to -0.02). Included cohort studies in children and adults most often do not suggest any relationship between total fat intake and later measures of weight, body fatness or change in body fatness. However, there was a suggestion that lower fat intake was associated with smaller increases in weight in middle-aged but not elderly adults, and in change in BMI in the highest validity child cohort.

AUTHORS' CONCLUSIONS

Trials where participants were randomised to a lower fat intake versus usual or moderate fat intake, but with no intention to reduce weight, showed a consistent, stable but small effect of low fat intake on body fatness: slightly lower weight, BMI and waist circumference compared with controls. Greater fat reduction and lower baseline fat intake were both associated with greater reductions in weight. This effect of reducing total fat was not consistently reflected in cohort studies assessing the relationship between total fat intake and later measures of body fatness or change in body fatness in studies of children, young people or adults.

Influence of a hyperlipidic diet on the composition of the non-membrane lipid pool of red blood cells of male and female rats

Background and objectives. Red blood cells (RBC) are continuously exposed to oxidative agents, affecting their membrane lipid function. However, the amount of lipid in RBCs is higher than the lipids of the cell membrane, and includes triacylglycerols, which are no membrane components. We assumed that the extra lipids originated from lipoproteins attached to the cell surface, and we intended to analyse whether the size and composition of this lipid pool were affected by sex or diet. Experimental design. Adult male and female Wistar rats were fed control or cafeteria diets. Packed blood cells and plasma lipids were extracted and analysed for fatty acids by methylation and GC-MS, taking care of not extracting membrane lipids. Results. The absence of ω3-PUFA in RBC extracts (but not in plasma) suggest that the lipids extracted were essentially those in the postulated lipid surface pool and not those in cell membrane. In cells' extracts, there was a marked depletion of PUFA (and, in general, of insaturation). Fatty acid patterns were similar for all groups studied, with limited effects of sex and no effects of diet in RBC (but not in plasma) fatty acids. Presence of trans fatty acids was small but higher in RBC lipids, and could not be justified by dietary sources. Conclusions. The presence of a small layer of lipid on the RBC surface may limit oxidative damage to the cell outer structures, and help explain its role in the transport of lipophilic compounds. However, there may be other, so far uncovered, additional functions for this lipid pool.

Palm Oil Consumption Increases LDL Cholesterol Compared with Vegetable Oils Low in Saturated Fat in a Meta-Analysis of Clinical Trials

BACKGROUND

Palm oil contains a high amount of saturated fat compared with most other vegetable oils, but studies have reported inconsistent effects of palm oil on blood lipids.

OBJECTIVE

We systematically reviewed the effect of palm oil consumption on blood lipids compared with other cooking oils using data from clinical trials.

METHODS

We searched PubMed and the Cochrane Library for trials of at least 2 wk duration that compared the effects of palm oil consumption with any of the predefined comparison oils: vegetable oils low in saturated fat, trans fat-containing partially hydrogenated vegetable oils, and animal fats. Data were pooled by using random-effects meta-analysis.

RESULTS

Palm oil significantly increased LDL cholesterol by 0.24 mmol/L (95% CI: 0.13, 0.35 mmol/L; I(2) = 83.2%) compared with vegetable oils low in saturated fat. This effect was observed in randomized trials (0.31 mmol/L; 95% CI: 0.20, 0.42 mmol/L) but not in nonrandomized trials (0.03 mmol/L; 95% CI: -0.15, 0.20 mmol/L; P-difference = 0.02). Among randomized trials, only modest heterogeneity in study results remained after considering the test oil dose and the comparison oil type (I(2) = 27.5%). Palm oil increased HDL cholesterol by 0.02 mmol/L (95% CI: 0.01, 0.04 mmol/L; I(2) = 49.8%) compared with vegetable oils low in saturated fat and by 0.09 mmol/L (95% CI: 0.06, 0.11 mmol/L; I(2) = 47.8%) compared with trans fat-containing oils.

CONCLUSIONS

Palm oil consumption results in higher LDL cholesterol than do vegetable oils low in saturated fat and higher HDL cholesterol than do trans fat-containing oils in humans. The effects of palm oil on blood lipids are as expected on the basis of its high saturated fat content, which supports the reduction in palm oil use by replacement with vegetable oils low in saturated and trans fat. This systematic review was registered with the PROSPERO registry at http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42012002601#.VU3wvSGeDRZ as CRD42012002601.

Australia's nutrition transition 1961-2009: a focus on fats

Since the 1960s, Australian diets have changed considerably, influenced by a burgeoning multicultural cuisine, increase in urbanisation and food technology advances. This has been described as a 'nutrition transition', resulting in the adoption of a Western diet pattern, with a shift away from unrefined foods towards a diet higher in both plant-derived high PUFA and total fats and refined carbohydrates. Utilising the 1961-2009 annual food supply data from the UN FAO, the present study investigated changes in the intake of macronutrient and specific fatty acid in the Australian population, including that of the PUFA linoleic acid (LA), due to its hypothesised role in inflammation and risk for obesity. Cumulative change over time for the contribution of specific nutrients to total available energy (TAE) was calculated, as was linearity of change. Over the time period analysed, the cumulative change in TAE from carbohydrate was -9.35 and +16.67 % from lipid. The cumulative change in TAE from LA was +120.48 %. Moreover, the cumulative change in the contribution of LA to total PUFA availability was +7.1 %. Utilising the average g/d per capita of LA from selected dietary sources, the change in the contribution of specific foodstuffs was assessed, with total plant oils having a cumulative change of +627.19 % to LA availability, equating to a cumulative change of +195.61 % in contribution to total LA availability. The results of the present study indicate that LA availability in Australia has increased over the previous five decades as a result of the availability of increased plant oils, as has total fat, possibly contributing to the increasing rates of obesity and obesity-associated co-morbidities.

Reduction in saturated fat intake for cardiovascular disease

BACKGROUND

Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally it is unclear whether the energy from saturated fats that are lost in the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein. This review is part of a series split from and updating an overarching review.

OBJECTIVES

To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA) or monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.

SEARCH METHODS

We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and EMBASE (Ovid) on 5 March 2014. We also checked references of included studies and reviews.

SELECTION CRITERIA

Trials fulfilled the following criteria: 1) randomised with appropriate control group; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) not multifactorial; 4) adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 5) intervention at least 24 months; 6) mortality or cardiovascular morbidity data available.

DATA COLLECTION AND ANALYSIS

Two review authors working independently extracted participant numbers experiencing health outcomes in each arm, and we performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses and funnel plots.

MAIN RESULTS

We include 15 randomised controlled trials (RCTs) (17 comparisons, ˜59,000 participants), which used a variety of interventions from providing all food to advice on how to reduce saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of cardiovascular events by 17% (risk ratio (RR) 0.83; 95% confidence interval (CI) 0.72 to 0.96, 13 comparisons, 53,300 participants of whom 8% had a cardiovascular event, I² 65%, GRADE moderate quality of evidence), but effects on all-cause mortality (RR 0.97; 95% CI 0.90 to 1.05; 12 trials, 55,858 participants) and cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 12 trials, 53,421 participants) were less clear (both GRADE moderate quality of evidence). There was some evidence that reducing saturated fats reduced the risk of myocardial infarction (fatal and non-fatal, RR 0.90; 95% CI 0.80 to 1.01; 11 trials, 53,167 participants), but evidence for non-fatal myocardial infarction (RR 0.95; 95% CI 0.80 to 1.13; 9 trials, 52,834 participants) was unclear and there were no clear effects on stroke (any stroke, RR 1.00; 95% CI 0.89 to 1.12; 8 trials, 50,952 participants). These relationships did not alter with sensitivity analysis. Subgrouping suggested that the reduction in cardiovascular events was seen in studies that primarily replaced saturated fat calories with polyunsaturated fat, and no effects were seen in studies replacing saturated fat with carbohydrate or protein, but effects in studies replacing with monounsaturated fats were unclear (as we located only one small trial). Subgrouping and meta-regression suggested that the degree of reduction in cardiovascular events was related to the degree of reduction of serum total cholesterol, and there were suggestions of greater protection with greater saturated fat reduction or greater increase in polyunsaturated and monounsaturated fats. There was no evidence of harmful effects of reducing saturated fat intakes on cancer mortality, cancer diagnoses or blood pressure, while there was some evidence of improvements in weight and BMI.

AUTHORS' CONCLUSIONS

The findings of this updated review are suggestive of a small but potentially important reduction in cardiovascular risk on reduction of saturated fat intake. Replacing the energy from saturated fat with polyunsaturated fat appears to be a useful strategy, and replacement with carbohydrate appears less useful, but effects of replacement with monounsaturated fat were unclear due to inclusion of only one small trial. This effect did not appear to alter by study duration, sex or baseline level of cardiovascular risk. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturated fats. The ideal type of unsaturated fat is unclear.

Effect of conjugated linoleic acid enrichment on the quality characteristics of Turkish dry fermented sausage

The effects of conjugated linoleic acid (CLA) enrichment on lipid oxidation, the fatty acid profile, physico-chemical, sensory and microbiological features of sucuk were investigated. The control sucuk did not contain CLA, however, other groups contained 0.5 %, 1 %, 1.5 %, 2 %, 2.5 %, and 3 % CLA, respectively. The results indicated that CLA concentration was increased in sucuk with CLA addition (p < 0.05). CLA concentration decreased (p < 0.05) during the fermentation period, but did not alter during the storage. Lipid oxidation gradually increased with the increasing of storage in all treatments (p < 0.05). However, addition of CLA decreased lipid oxidation compared to control (p < 0.05). With regard to color, higher L* values were observed in 2 % CLA treatment group compared to other treatments during storage (p < 0.05). Moreover, CLA addition resulted in increased a* values in sucuk (p < 0.05). With the addition of CLA, saturated fatty acids in sucuk decreased and poly-unsaturated fatty acids and conjugated linoleic acids increased (p < 0.05).

Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes

BACKGROUND/OBJECTIVES

The contemporary American diet figures centrally in the pathogenesis of numerous chronic diseases--'diseases of civilization'--such as obesity and diabetes. We investigated in type 2 diabetes whether a diet similar to that consumed by our pre-agricultural hunter-gatherer ancestors ('Paleolithic' type diet) confers health benefits.

SUBJECTS/METHODS

We performed an outpatient, metabolically controlled diet study in type 2 diabetes patients. We compared the findings in 14 participants consuming a Paleo diet comprising lean meat, fruits, vegetables and nuts, and excluding added salt, and non-Paleolithic-type foods comprising cereal grains, dairy or legumes, with 10 participants on a diet based on recommendations by the American Diabetes Association (ADA) containing moderate salt intake, low-fat dairy, whole grains and legumes. There were three ramp-up diets for 7 days, then 14 days of the test diet. Outcomes included the following: mean arterial blood pressure; 24-h urine electrolytes; hemoglobin A1c and fructosamine levels; insulin resistance by euglycemic hyperinsulinemic clamp and lipid levels.

RESULTS

Both groups had improvements in metabolic measures, but the Paleo diet group had greater benefits on glucose control and lipid profiles. Also, on the Paleo diet, the most insulin-resistant subjects had a significant improvement in insulin sensitivity (r = 0.40, P = 0.02), but no such effect was seen in the most insulin-resistant subjects on the ADA diet (r = 0.39, P = 0.3).

CONCLUSIONS

Even short-term consumption of a Paleolithic-type diet improved glucose control and lipid profiles in people with type 2 diabetes compared with a conventional diet containing moderate salt intake, low-fat dairy, whole grains and legumes.

Apolipoprotein E isoforms 3/3 and 3/4 differentially interact with circulating stearic, palmitic, and oleic fatty acids and lipid levels in Alaskan Natives

Lifestyle changes in Alaskan Natives have been related to the increase of cardiovascular disease and metabolic syndrome in the last decades. Variation of the apolipoprotein E (Apo E) genotype may contribute to the diverse response to diet in lipid metabolism and influence the association between fatty acids in plasma and risk factors for cardiovascular disease. The aim of this investigation was to analyze the interaction between Apo E isoforms and plasma fatty acids, influencing phenotypes related to metabolic diseases in Alaskan Natives. A sample of 427 adult Siberian Yupik Alaskan Natives was included. Fasting glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, Apo A1, and Apo B plasma concentrations were measured using reference methods. Concentrations of 13 fatty acids in fasting plasma were analyzed by gas chromatography, and Apo E variants were identified. Analyses of covariance were conducted to identify Apo E isoform and fatty acid main effects and multiplicative interactions. The means for body mass index and age were 26 ± 5.2 and 47 ± 1.5, respectively. Significant main effects were observed for variation in Apo E and different fatty acids influencing Apo B levels, triglycerides, and total cholesterol. Significant interactions were found between Apo E isoform and selected fatty acids influencing total cholesterol, triglycerides, and Apo B concentrations. In summary, Apo E3/3 and 3/4 isoforms had significant interactions with circulating levels of stearic, palmitic, oleic fatty acids, and phenotypes of lipid metabolism in Alaskan Natives.

Grain Nutrient Composition of Maize (Zea mays L.) Drought-Tolerant Populations

A total of 13 maize populations from the drought-tolerant mini core collection from Maize Research Institute gene bank were evaluated for oil, protein, and tryptophan contents, fatty acid (FA) composition, and kernel characteristics. All accessions are high oil (5.8-7.9%) and protein (10.58-12.45%) genotypes. Most of the accessions showed high contents of tryptophan (0.070-0.081%) and saturated (12.65-17.91%) and monounsaturated (24.19-45.52%) FAs. Significant positive correlations were found between oil and protein and between oil and tryptophan contents (p < 0.01). Correlations between oil and principal FA were non-significant. Several accessions showed multiple nutritional advantages. For example, IP6428 had high oil (7.3%), tryptophan (0.081%), and saturated FA (17.9%) contents. Moreover, a positive correlation (p < 0.01) between palmitic (13.68%) and oleic (34.74%) acids enables the use of IP6428 for developing lines high in these FAs. Because drought-tolerant accessions were selected in both subtropical and temperate zones, they could be used for breeding value-added maize adapted to both environments.

Effects of diets high in unsaturated Fatty acids on socially induced stress responses in Guinea pigs

Unsaturated fatty acids (UFAs), such as omega-3 and omega-6 poly- and omega-9 monounsaturated fatty acids are important nutrients and major components of neuronal cell membranes. They play a major role in modulating brain functions and physiology and may therefore diminish behavioral and physiological stress reactions in corroboration with decreased cortisol concentrations. Functionally, cortisol itself can modulate several behaviors and also the fatty acid metabolism in the long term. But only little is known about the behavioral and physiological influences of dietary UFAs in a social group, where individuals are regularly exposed to stressful situations. Therefore, the aim of this study was to determine the effects of dietary UFAs on saliva cortisol concentrations and behavioral responses in socially confronted guinea pigs. Three groups of animals were additionally supplemented with 500 mg chia seeds (high in omega-3), walnuts (high in omega-6), or peanuts (high in omega-9) per kg bodyweight each day and compared to a control group. During social confrontation saliva cortisol concentrations significantly increased in all groups, which was accompanied by a loss in bodyweight. However, cortisol levels remained lower in the chia and walnut groups compared to controls. Additionally, the walnut group displayed significantly increased locomotion, while no differences between groups were detected in socio-positive, sexual, or aggressive behaviors. Total plasma omega-3, omega-6, and omega-9 fatty acids were significantly increased in the corresponding groups, due to the dietary supplementations. However, a significant decrease in plasma omega-3 and an increase in plasma n-6 fatty acids were detected in the chia group when comparing the measurements before and after social confrontation. We conclude that both omega-3 and omega-6 polyunsaturated fatty acids can diminish behavioral and physiological stress responses to the social environment, enabling individuals to cope with social stressors, but at the expense of plasma derived omega-3 fatty acids.

High-oleic canola oil consumption enriches LDL particle cholesteryl oleate content and reduces LDL proteoglycan binding in humans

Oleic acid consumption is considered cardio-protective according to studies conducted examining effects of the Mediterranean diet. However, animal models have shown that oleic acid consumption increases LDL particle cholesteryl oleate content which is associated with increased LDL-proteoglycan binding and atherosclerosis. The objective was to examine effects of varying oleic, linoleic and docosahexaenoic acid consumption on human LDL-proteoglycan binding in a non-random subset of the Canola Oil Multi-center Intervention Trial (COMIT) participants. COMIT employed a randomized, double-blind, five-period, cross-over trial design. Three of the treatment oil diets: 1) a blend of corn/safflower oil (25:75); 2) high oleic canola oil; and 3) DHA-enriched high oleic canola oil were selected for analysis of LDL-proteoglycan binding in 50 participants exhibiting good compliance. LDL particles were isolated from frozen plasma by gel filtration chromatography and LDL cholesteryl esters quantified by mass-spectrometry. LDL-proteoglycan binding was assessed using surface plasmon resonance. LDL particle cholesterol ester fatty acid composition was sensitive to the treatment fatty acid compositions, with the main fatty acids in the treatments increasing in the LDL cholesterol esters. The corn/safflower oil and high-oleic canola oil diets lowered LDL-proteoglycan binding relative to their baseline values (p = 0.0005 and p = 0.0012, respectively). At endpoint, high-oleic canola oil feeding resulted in lower LDL-proteoglycan binding than corn/safflower oil (p = 0.0243) and DHA-enriched high oleic canola oil (p = 0.0249), although high-oleic canola oil had the lowest binding at baseline (p = 0.0344). Our findings suggest that high-oleic canola oil consumption in humans increases cholesteryl oleate percentage in LDL, but in a manner not associated with a rise in LDL-proteoglycan binding.

Effect of pistachio nut consumption on endothelial function and arterial stiffness

OBJECTIVES

Previous studies have demonstrated beneficial effects of regular consumption of pistachio nuts on glycemic, lipid, and oxidative stress parameters. The aim of this study was to determine its effect on vascular health, which has not been adequately studied so far.

METHODS

In this open label, randomized parallel-group study, 60 adults with mild dyslipidemia were randomized to lifestyle modification (LSM) alone or LSM with consumption of 80 g (in-shell) pistachios (equivalent to 40 g or 1.5 oz shelled pistachios) daily for 3 mo. Biochemical parameters, brachial artery flow-mediated vasodilation (BAFMD), and carotid-femoral and brachial-ankle pulse wave velocity (cfPWV and baPWV, respectively) were measured before and after the intervention.

RESULTS

At 3 mo, there was no change in any of the clinical or biochemical parameters in the LSM group. However, the patients in the pistachio group had a significant increase in high-density lipoprotein cholesterol (HDL-C; 35.7 ± 8.8 mg/dL versus 37.8 ± 10.1 mg/dL; P = 0.04) and a reduction in low-density lipoprotein cholesterol (137.2 ± 32.6 mg/dL versus 127.6 ± 34.0 mg/dL; P = 0.02), total cholesterol (TC)-to-HDL-C ratio (5.8 ± 1.3 mg/dL versus 5.3 ± 1.1 mg/dL; P = 0.001), and fasting blood sugar (88.8 ± 7.1 mg/dL versus 86.6 ± 6.3 mg/dL; P = 0.05). Additionally, whereas LSM alone was associated with no improvement in BAFMD or PWV, individuals in the pistachio group had significant reduction in left baPWV (1261.7 ± 187.5 cm/sec versus 1192.4 ± 152.5 cm/sec; P = 0.02) and statistically nonsignificant improvement in most other parameters, including BAFMD. As a result, at 3 mo the patients in the pistachio group had lower cfPWV (770.9 ± 96.5 cm/sec versus 846.4 ± 162.0 cm/sec; P = 0.08), lower left baPWV (1192.4 ± 152.5 cm/sec versus 1326.3 ± 253.7 cm/sec; P = 0.05), and lower average baPWV (1208.2 ± 118.4 cm/sec versus 1295.8 ± 194.1 cm/sec; P = 0.08) compared with the LSM group. Two-way analysis of variance revealed significant treatment effect of pistachio consumption on cfPWV, left baPWV, average baPWV, and BAFMD (P = 0.037, 0.01, 0.07, and 0.046, respectively).

CONCLUSIONS

The present study demonstrates that regular consumption of pistachio nuts not only improves glycemic and lipid parameters, but also results in improvements in vascular stiffness and endothelial function. Importantly, these improvements were seen in apparently healthy individuals and with a diet (including pistachios) and exercise regimen that every adult individual is expected to follow.